i don't know. it's a cool poc.

src/bg.js

@@ -51,6 +51,8 @@ var registerToTST = async function() {
 			// The name of your addon (string, optional)
 			name: MY_EXTENSION_NAME
 		});
+
+		updateAllColorsOnAllTabs();
 	} catch (e) {
 		// TST is not available
 	}
@@ -78,6 +80,25 @@ var getTabParent = (tabs, id, currentTopLevelTabPos) => {
 	}
 };
 
+var updateAllColorsOnAllTabs = async () => {
+	let allWindows = await browser.windows.getAll();
+	allWindows.forEach(async w => {
+		var tstTabs = await browser.runtime.sendMessage(kTST_ID, {
+			type: 'get-tree',
+			window:  w.id
+		});
+
+		for (let i = 0; i < tstTabs.length; i++) {
+			if (tstTabs[i].status === 'complete') {
+				browser.tabs.executeScript(tstTabs[i].id, {
+					code: '(' + changeIcon.toString() + ')("' + generateRandomColor(getTabParent(tstTabs, tstTabs[i].id)) + '")'
+				});
+			}
+		}
+	});
+
+}
+
 //events
 //register to tst
 browser.runtime.onMessageExternal.addListener((aMessage, aSender) => {
@@ -98,12 +119,9 @@ browser.tabs.onUpdated.addListener(async (tabId, changeInfo, tab) => {
 	});
 
 	if (tab.status === 'complete') {
-		console.log(changeIcon.toString() + '(' + generateRandomColor(getTabParent(tstTab, tab.id)) + ')');
-
 		browser.tabs.executeScript(tab.id, {
 			code: '(' + changeIcon.toString() + ')("' + generateRandomColor(getTabParent(tstTab, tab.id)) + '")'
 		});
-		changeIcon(generateRandomColor(getTabParent(tstTab, tab.id)));
 	}
 });